Once when I was a courier, a few of us were sitting on a bench in front of a building and a lawyer came outside while on his cel phone and decided the rack on my bike (I often handled cargo) was a dandy place for him to open up his briefcase and have a conference. Not quite the same as having someone stick trash in my water bottle cage, but you story reminded me of it. The people I was with thought I was going to either chew the guy out or worse, but I was so flabbergasted I just stared at him. People can be so incredibly selfish and self absorbed sometimes.